zac510 wrote:So in a sense it could just be interpreted as extremely slow rebound damping and people probably wouldn't consider adjusting the rebound damping to be illegal.

Definitely goes to show how integrate vehicle dynamics are. There's not just simply one thing that does one job. They are all influencing another, all the time.

The system must be more dynamic than that. If it was just an extremely slow rebound then it would hurt them through a series of bends. If it is as simple as you're saying then, yes, I'm sure there's nothing illegal about it so there will be no problems come the season start.

For reference, this is what is described in the Ferrari letter:

'In all cases they would be installed between some combination of the sprung part of the car and the two suspension rockers on a single axle, and achieve an effect similar to that of a FRIC system without requiring any connection between the front and rear of the car. All suspension devices in question feature a moveable spring seat and they use energy recovered from wheel loads and displacements to alter the position of the heave spring.

“Their contribution to the primary purpose of the sprung suspension – the attachment of the wheels to the car in a manner which isolates the sprung part from road disturbances – is small, while their effect on ride height and hence aerodynamic performance is much larger, to the extent that we believe it could justify the additional weight and design complexity.
F1 suspension

“We would therefore question the legality of these systems under Art. 3.15 and its interpretation in TD/002-11, discriminating between whether certain details are ‘wholly incidental to the main purpose of the suspension system’ or ‘have been contrived to directly affect the aerodynamic performance of the car’.
The two areas that Resta requested be clarified in detail were: “1) displacement in a direction opposed to the applied load over some or all of its travel, regardless of the source of the stored energy used to achieve this.
“2) a means by which some of the energy recovered from the forces and displacements at the wheel can be stored for release at a later time to extend a spring seat or other parts of the suspension assembly whose movement is not defined by the principally vertical suspension travel of the two wheels.”

This doesn't sound to me simply like a slow rebound damping system and is what Charlie has said is probably illegal. The words 'wholly incidental to the main purpose of the suspension system' are important to note. What you describe is not 'wholly incidental' it's fundamental to the suspension system. So if Red Bull's system is as you describe, then I'm sure there won't be any problem whatsoever and everyone's happy.

I guess then that means suspension can be as complex as you like as long as it's not externally powered to adjust ride height. In other words active suspension isn't prohibited as long as it functions by purely passive and mechanical means.

The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

bonjon1979 wrote:.... “1) displacement in a direction opposed to the applied load over some or all of its travel, regardless of the source of the stored energy used to achieve this....

I'm not sure about this.

It is possible to alter the vehicle ride height without requiring the displacement of the device to oppose the applied load, and without explicitly storing energy.

Here is an (extreme) example. Two runs, shown in red & green, taken from a sinusoidal input test. Each has been processed to show minimum, maximum and average values of the time history of the front damper position. The plots were obtained from one rig test of a mid-engined GP vehicle, using the same input, the same vehicle, the same ballast, the same springs. The only difference was damper settings.... There is a 9 mm difference in average damper position of the two runs at 14 seconds.

godlameroso wrote:I guess then that means suspension can be as complex as you like as long as it's not externally powered to adjust ride height. In other words active suspension isn't prohibited as long as it functions by purely passive and mechanical means.

bonjon1979 wrote:.... “1) displacement in a direction opposed to the applied load over some or all of its travel, regardless of the source of the stored energy used to achieve this....

I'm not sure about this.

It is possible to alter the vehicle ride height without requiring the displacement of the device to oppose the applied load, and without explicitly storing energy.

Here is an (extreme) example. Two runs, shown in red & green, taken from a sinusoidal input test. Each has been processed to show minimum, maximum and average values of the time history of the front damper position. The plots were obtained from one rig test of a mid-engined GP vehicle, using the same input, the same vehicle, the same ballast, the same springs. The only difference was damper settings.... There is a 9 mm difference in average damper position of the two runs at 14 seconds.

Was the changed setting from red to green decreased rebound damping?

The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

Regarding the tendency of a damper to cause a spring to remain compressed or extended during a long period of excitation, say 10 seconds or more (if I'm interpreting this discussion correctly): is it a matter of creating an asymmetry between rebound and compression rates? If so, what's the relationship?

roon wrote:Regarding the tendency of a damper to cause a spring to remain compressed or extended during a long period of excitation, say 10 seconds or more (if I'm interpreting this discussion correctly): is it a matter of creating an asymmetry between rebound and compression rates? If so, what's the relationship?

Excess rebound can only cause a car to jack down as the shock doesn't allow the spring to come back to resting height fast enough before the next bump that further compresses the suspension which eventually causes the car to ride the bump rubber or packer or whatever.

Excess compression means the shock responds slower than spring compression over a bump.

It gets a bit more complex when you consider fast and slow damper motion, but that's the gist of it.

Translating that to your question

Lowering compression and increasing rebound will allow the spring to compress but not extend as much in relation to perfect damping, until jacking down occurs.

Increasing compression and lowering rebound will resist spring compression but allow extension until the car starts hopping around. The lack of rebound will add a second order bounce to the initial shock and spring resistance.

Again different damping speeds(slow and fast) make this a bit more complex and not as linear, as well as the physical properties of the shock itself, like valving, and tube material, and piston design and physical limitations.

That's about as simple as I can make it.

The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee